Lycoming and Prop Balance

[Darin Watson]

First off...NO affiliation or personal conflict.

I ran across this device the other day and was wondering if anyone is using it and would have feedback on effectiveness? http://balancemasters.com/ultralights/lycoming.html

Seem pretty simple and don't see a downside, but I am far from being any kind of engine/prop guru.

[Neal@F14]

From the website, it looks to be a fluid-filled (elemental mercury) harmonic balancer ring. Looks rather small to really do much good on a Lycoming. The website doesn't say how much it weighs or how much mercury it contains.

Years ago, Landoll made balancing rings that had a heavy steel ring contained with heavy silicone dampening fluid inside an aluminum housing that bolted onto the front side of a Lycoming flywheel. Some folks loved them, some hated them.

I have a solid steel Landoll inertia ring on my flywheel and not only do I need it for adding some weight up front for CG purposes, it really does smooth things out and let me idle smoother with lower rpms with a lightweight composite prop.

The Landoll rings (both solid and fluid/ring filled) are around 12 lbs in weight.

The mercury-filled small diameter flywheel ring is an interesting concept, but I'd bet it would never come close to the smoothness you'll get from a normal dynamic prop balancing procedure done by someone with experience and proper test equipment.

[BillL]

The visconic dampers are for torsional damping and I have never heard any claims for balancing. The silicone filled visconic damper and this mercury thing are different animals.

Here is a thread about dynabeads for tires using the same principle for balancing wheels.

http://www.vansairforce.com/communit...ad.php?t=82109

Being an engineer I am curious about the physics, a spinning bottle in a drill don't do it for me. Sacrificing an inner tube to test it out seems like a fun thing to do.

[Darin Watson]

I do believe that the statements regarding "two different animals" is correct...the balance master product is for "high speed", if one can call 2000-2700 high speed, balance in the X-Y plane and not for light props and low idle smoothness which is a spinning inertia issue.

I had my prop/engine dynamically balanced a couple years ago and could feel the difference; but also realize that there is an "optimal RPM" around which the balance is closest to "perfect" and all others RPMs are a compromise. The other thing is that I noticed is the relatively small weight increments that were required to get below the recommended 2 ips.

For the record my setup is an O-320 with Hartzel CS prop, so operation over a wider "optimal" RPM range would be advantageous. [Note: I'll leave optimal to the widest possible interpretation]

...looking for the guru's out there to weigh in!

[rockwoodrv9]

I have a question that this discussion has made me wonder about. I am building a 9A and I want a Catto prop mostly to cut vibration down. My uninformed opinion is vibrations are the problem for many more problems than given credit for.

With a O-320 in front, a Catto prop, and light weight battery, I will need a weight in front to give me the baggage limits I want.

My question - with a wood or composite prop with one of these weight-balancing plates, if there was a prop strike, would there be a better chance the crank is toast or a better chance it is ok?

As long as I am going to need a plate, maybe this type of vibration dampener is better than a standard plate?

[AX-O]

Originally Posted by Darin Watson

The other thing is that I noticed is the relatively small weight increments that were required to get below the recommended 2 ips.

The standard is below 0.2 ips not 2.

[Darin Watson]

...I stand corrected 0.2 ips.

[BillL]

Originally Posted by Darin Watson

I do believe that the statements regarding "two different animals" is correct...the balance master product is for "high speed", if one can call 2000-2700 high speed, balance in the X-Y plane and not for light props and low idle smoothness which is a spinning inertia issue.

I had my prop/engine dynamically balanced a couple years ago and could feel the difference; but also realize that there is an "optimal RPM" around which the balance is closest to "perfect" and all others RPMs are a compromise. The other thing is that I noticed is the relatively small weight increments that were required to get below the recommended 2 ips.

For the record my setup is an O-320 with Hartzel CS prop, so operation over a wider "optimal" RPM range would be advantageous. [Note: I'll leave optimal to the widest possible interpretation]

...looking for the guru's out there to weigh in!

I went out for a walk and after a while my feet hurt so I came home and sat down and took off my hat. My feet began to feel better. That hat made my feet hurt so I won't be wearing it again.

The Hg balancer is for a rotating imbalance, NOT a torsional excitation. The ring either just adds inertia (fixed) or not (fluid filled ring) but the fluid filled ring addresses the torsional issues. See this video, the guy is a little goofy but correct in his description for the damper and the hg filled tube. One is not a replacement for the other.
http://www.youtube.com/watch?v=Wa8P9loCuF4
IPS, inches per second is a linear measurement, radians per second is a torsional measure. I visited the Hartzell factory and their products are balanced at the end of the production line. The typically only took a single #10 size washer to balance. Having just built my spinner, I suspect it is horrible by comparison and will get the assembly balanced on the plane when running.

Imagine the voice of Alec Guinness (Obi-Wan), " search your feelings, Darin, you know this to be true"

I have sketched through the physics and now understand this hg or bead thing will work, in theory. Reality is different, so it is not a sure thing.

[Checkeredflagmark]

They are better than a conventional balance with a fixed weight due to the fact that the fluid is allowed to move within the ring when eng is in operation. Hence the word "Active" balances at all RPM's not just one, like a fixed weight !!!
I have installed several on both Lycomings and Continentals with much success.
Install one on your engine. You wont be sorry!
Balance Masters Active Vibration Dampeners can be purchased from Checkered Flag Restorations in California. There phone number is 661-305-9617 or Email checkeredflagrestorations@gmail.com

[Greenley]

Is anyone using one of these (balance masters), thoughts? Had a friend just look at them at Reno, and tried one on his Mooney, smoother and added 200rpm to his top end.